Yes there are differences between the two. Curious, but what aspect of your script/UI is it that is not working?
event handlers aren't working.
just a simple scaling script.
select something on the to artboard
execute script (window pops up)
you choose a scale from a dropdown list and the size of the object updates in a textedit box.
you can enter a dimension to scale and the artword updates.
theres a little more to it bat that's the gist of it.
anyway everyhing shows up on the dialog box (even dinamically generated scales list), but event handlers don't work and they do work as a window or palette.
i stripped down the script to see what i can actually get working and it seems all i can do is execute prompts and alerts. just curious that's all. palette works just fine.
...but it doesnt work as a dialog just palette.
it is usually the other way around, dialogs work, palettes don't.
post your code, it is hard to tell without looking at it.